Trichanthera
Content
Description
Shrubs or trees with minute cystoliths. Shoots articulated, obtusely quadrangular, robust. Leaves opposite, petiolate; blades, ovate to oblong, subcoriaceous, margin entire to undulate. Inflorescences dense, terminal, many-flowered panicles or corymbs, flowers arranged in triads; bracts small, central flower of each triad ebracteolate and lateral flowers subtended by 2triangular bracteoles at base of calyx; pedicels about as long as bracts. Flowers conspicuous, distally densely pubescent; calyx campanulate, deeply 5-lobed, lobes subequal to equal in size, mostly obtuse apically; corolla campanulate, densely silky or tomentose, lower half of tube cylindric, gradually enlarged upwards, limb regular, 5-lobed, lobes red proximally, yellowish distally, red within, subequal, triangular, contorted in bud; stamens 4, didynamous, inserted in middle of corolla tube, exserted from mouth of corolla, filaments united into pairs at base, anthers 2-thecous, thecae equal in size, parallel, introrsely ciliate in a longitudinal line, obtuse or rounded at both ends, staminodes 0; disk annular; ovary with 3 or 4 ovules in each locule, stigma 2-lobed, upper lobe rudimentary, lower lobe oblong. Capsules estipitate, ellipsoidal, pubescent, retinacula present, septae with attached retinacula remaining attached to inner capsule wall; seeds 4, 2 in each locule, lenticular.
Distribution
C America present, Guianas present, Southern America: Peru (Peru present)
Ranging from C America southward to Peru and Brazil; a genus of 2 species and 1 variety found in moist lowland forests, frequently along streams and swampy areas; in the Guianas 1 species and 1 variety.
Wood
Growth rings absent.
Vessels diffuse, solitary for 30%, the remainder in radial multiples of 2-3, few clusters, 8 (5-11) per sq. mm, outline elliptic, diameter 150 (120-190) µm. Vessel member length 770 (300-1200) µm. Perforations simple, intervascular pits 5-6 µm, often slits confluent; vessel/ray pitting of two sizes: (1) like the intervessel pitting, and (2) large, longitudinal, both types present in the same cell.
Rays uni- and multiseriate 4-5 per mm. The uniseriates few, composed of upright cells, the multiseriates 3-5 cells wide, the body of procumbent and square cells, margin usually 1-2 cells high, occasionally much higher; sheath cells present in some rays. Width 60-80 µm, height up to 3 mm. More or less translucent cystoliths frequently present.
Parenchyma scarce, restricted to a few vasicentric strands, seldom forming a complete ring. Strands of 2-4 cells.
Ground tissue of thin-walled septate fibres. Diameter 23-40 µm, walls 4.5 µm thick, occasionally gelatinous. Pits simple, numerous in radial walls, less frequently in tangential walls. Length 1500 (900-2000) µm. F/V ratio: 1.97.
Vessels diffuse, solitary for 30%, the remainder in radial multiples of 2-3, few clusters, 8 (5-11) per sq. mm, outline elliptic, diameter 150 (120-190) µm. Vessel member length 770 (300-1200) µm. Perforations simple, intervascular pits 5-6 µm, often slits confluent; vessel/ray pitting of two sizes: (1) like the intervessel pitting, and (2) large, longitudinal, both types present in the same cell.
Rays uni- and multiseriate 4-5 per mm. The uniseriates few, composed of upright cells, the multiseriates 3-5 cells wide, the body of procumbent and square cells, margin usually 1-2 cells high, occasionally much higher; sheath cells present in some rays. Width 60-80 µm, height up to 3 mm. More or less translucent cystoliths frequently present.
Parenchyma scarce, restricted to a few vasicentric strands, seldom forming a complete ring. Strands of 2-4 cells.
Ground tissue of thin-walled septate fibres. Diameter 23-40 µm, walls 4.5 µm thick, occasionally gelatinous. Pits simple, numerous in radial walls, less frequently in tangential walls. Length 1500 (900-2000) µm. F/V ratio: 1.97.
Notes
Specimens of Trichanthera are sometimes confused with those of the genus Bravaisia , but can be distinguished from the latter by basally rounded and awnless anther thecae, flowers borne on pedicels 2-11 mm long, and capsule which are pubescent at maturity. The anther thecae in Bravaisia are basally awned with a single, subulate projection, the flowers are sessile or borne on pedicels less than 2 mm long, and the capsules are glabrous at maturity.